Modernism in music is characterized by a desire for or belief in progress and science, surrealism, anti-romanticism, political advocacy, general intellectualism, and/or a breaking with the past or common practice.

Modernism was essentially an outgrowth of historicism in that it presupposes a composer's knowledge of his place in music history, and has roots in the ideas of mid-19th-century philosophers such as Hegel. In music it developed due to social factorsвАФthe public concert in its current form, and the attendant formation of a "canon" of past masterworks that were performed regularly, instead of sinking into stylistic obsolescence as consumers' tastes moved onвАФas well as the purely musical void left by the death of Beethoven (around whom an extensive mythology had already congealed).[citation needed] The first notable exponent of modernism in music was Franz Liszt, whose so-called New German School (the term was introduced by influential critic Franz Brendel) sought a conscious break with the music of the past. The best-known composer sometimes considered affiliated with this school of thought was Richard Wagner.

The New German School's proto-modernist ideology grew around a kernel of German nationalism, as impliedвАФalthough Brendel was willing to make composers he liked into "honorary Germans"вАФand much of it was abandoned, particularly by composers and critics who were not German. The music it produced, however, survived, particularly in the operas of Wagner, which proved enormously influential on such late-nineteenth-century composers as Debussy, Mahler, Schoenberg, and Richard Strauss. Many of the composers influenced by Wagner developed, consciously or unconsciously, a desire to reject or break from the tradition he expounded. The modernists went much further than this. While much late-romantic music pulled at or suspended tonality, Schoenberg was probably the first to call for a complete break from it as a matter of doctrine. And thus modernism: tonality was rejected because music had to exhibit progressive stylistic development and others had already stretched tonal music to the breaking point. By 1909, Schoenberg had abandoned tonality for the most part, and he was not alone. A commitment to "perpetual innovation" soon became inherent in modernism, with Schoenberg going on to develop a twelve-note technique to replace tonality as a determining system and others going on to do completely different things (Igor Stravinsky, for example, became involved with primitivism and neoclassicism). This plurality of individual styles was also inherent to modernism, with its emphasis on inwards expression and personal originality. Modernism produced a few works that achieved real popular successвАФmost notably, the tone poems of Richard Strauss, the symphonies of Gustav Mahler and Dmitri Shostakovich, the violin concertos, Third Piano Concerto, First and Fifth Symphonies, and several ballets by Sergei Prokofiev, Stravinsky's Firebird, Petrushka, Sacre du printemps, and Symphony of Psalms, and Bart√≥k's Third Piano Concerto and Concerto for OrchestraвАФand, whether or not one considers the chain of "progressive" musical reactions it set off to be modernistic as well, has had a practically inescapable influence, touching contemporary art composition, many genres of pop music, film scores and theatre.